cho sin a = căn 3/2 tính cos a tan a cot a

Đáp án:

 \(\sin\alpha=\dfrac12.\\\tan\alpha=\sqrt3.\\\cot\alpha=\dfrac1{\sqrt3}.\)

Giải thích các bước giải:

 Ta có:

\(\sin^{2}\alpha+\cos^{2}\alpha=1\\\Rightarrow (\dfrac{\sqrt3}2)^{2}+\cos^{2}\alpha=1\\\Rightarrow \dfrac34+\cos^{2}\alpha=1\\\Rightarrow \cos^{2}\alpha=1-\dfrac34=\dfrac14\\\Rightarrow \cos\alpha=\dfrac12.\\\text{_____________}\\\tan\alpha=\dfrac{\sin\alpha}{\cos\alpha}=\dfrac{\sqrt3}2:\dfrac12=\sqrt3.\\\text{_____________}\\\cot\alpha=\dfrac{1}{\tan\alpha}=\dfrac{1}{\sqrt3}.\)

`@nguyen``nam500#hoidap247`.